Does it seem like lean has been under attack recently? For example, several lean proponents were up in arms in the wake of a July article in the Wall Street Journal. The article outlined component shortages faced by Apple and Nissan Motor, and concluded that in part "the drawbacks of lean manufacturing methods" were to blame, augmented by an overstretched global supply chain. Shoddy investigative reporting, commented one lean proponent about the article. Apple has never been considered a lean company, pointed out another. Lean has been completely misconstrued, said yet a third.

Toyota's recent woes, too, have been cited as an example of the failure of lean, a position frequently opposed by those who claim the failure was Toyota's straying from its own Toyota Production System (TPS), the epitome of a lean production system.

At the other end of the spectrum are the manufacturing companies and plants that extol the great productivity and other operational gains they have reaped through their implementations of lean manufacturing. Indeed, over the past five years more than 90% of finalists and winners of IndustryWeek's own Best Plants competition, which recognizes manufacturing excellence, reported implementing lean manufacturing to a significant degree or more. Those same plants reported median 30% reductions in manufacturing cycle times over the past three years, median scrap reductions of 33% and median productivity improvements of 24%.

Why the diversity of opinions regarding lean? If you speak with lean experts, a possible answer rears its head. That answer is that people are confused -- both about what defines lean as well as how to implement lean. Get that confusion straightened out and the value of lean as a driver of operational excellence grows more apparent.

What is Lean?

What precisely constitutes "lean" has been a challenge for many since the term joined the manufacturing lexicon more than 15 years ago. The term was coined by researchers led by James Womack to describe how Toyota ran its business. On Womack's Lean Enterprise Institute website, lean's core idea is described in this way: "to maximize customer value while minimizing waste. Simply, lean means creating more value for customers with fewer resources." Lean thinking, the explanation continues, "changes the focus of management from optimizing separate technologies, assets, and vertical departments to optimizing the flow of products and services through entire value streams that flow horizontally across technologies, assets, and departments to customers."

In reality, the definition of lean frequently varies depending upon whom you speak with -- whether it should or not. "I have always said if you had 100 lean practitioners in the room and asked for a definition, you might get 80 answers and about 20 themes, mostly around the tools of lean," says Sue Gillman, a partner with Aveus LLC.